In classical physics, the positive cannot exist without the negative, and vise-versa. Nikola Tesla documented what he believed was a way to create a monopole, and derrive therefrom an unlimited source of free power. He was never able to test his equations in the hard world, and since his death nobody else has attempted either :o)
Interesting that you mention him. There are some stories about his “suspicious” demise....don’t know if you’ve read about them. Has to do with Bush and other folks. What was done to him, and his inventions, just ain’t right.
What says Hawking? I don’t know much about the subject, but have always been interested.